Gamma radiation is electromagnetic radiation similar to x-rays except that gamma rays originate in the nucleus of an atom whereas x-rays originate in the extranuclear structure. Gamma rays usually have higher energies and correspondingly shorter wavelengths than x-rays. Gamma radiation is highly penetrating and usually accompanies alpha and beta emissions and always accompanies fission.
Present day dosimeters to detect and measure gamma radiation such as geiger counters and solid state detectors require complicated circuitry and mechanical manipulation to detect the presence of gamma radiation.